CVE-2026-71456 in Kantech Entrapass
Summary
by MITRE • 10/26/2026
Use of hard-coded cryptographic key vulnerability in Johnson Controls Kantech Entrapass allows Padding Oracle Crypto Attack.
This issue affects Kantech Entrapass: before 9.20.
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Analysis
by VulDB Data Team • 10/26/2026
The identified vulnerability within Johnson Controls Kantech Entrapass versions prior to 9.20 represents a critical failure in cryptographic implementation, specifically categorized under CWE-321 as the use of hard-coded encryption keys. This flaw stems from the inclusion of static cryptographic material directly within the application binary or configuration files rather than deriving them dynamically through secure key management protocols. The presence of these fixed keys allows an attacker to perform padding oracle attacks, a sophisticated cryptanalytic technique that exploits the error messages returned by decryption routines when invalid padding is detected. By carefully crafting and submitting malformed ciphertexts to the vulnerable service, an adversary can iteratively deduce the plaintext content without possessing the actual encryption key, effectively bypassing confidentiality controls entirely.
From a technical perspective, this vulnerability leverages the predictable behavior of block cipher modes such as CBC or CFB when they process improperly padded data. The application likely fails to implement constant-time comparison for padding validation or leaks timing information through distinct error responses for different types of decryption failures. This side-channel leakage enables an attacker to reconstruct sensitive data byte by byte. In the context of access control systems like Entrapass, this capability is particularly dangerous as it may allow unauthorized individuals to decrypt stored credentials, audit logs containing entry and exit times, or configuration settings that define system security policies. The exploitation does not require high-level privileges on the host machine but rather network accessibility to the affected service endpoints, making remote exploitation feasible for attackers within the same local area network segment.
The operational impact of this vulnerability extends beyond simple data exfiltration. Compromise of these cryptographic secrets can lead to a complete breakdown of trust in the access control infrastructure. Attackers could potentially forge authentication tokens or manipulate historical records to cover their tracks, thereby undermining the integrity and non-repudiation guarantees that such systems are designed to provide. Furthermore, if the hard-coded keys are shared across multiple installations due to poor key lifecycle management, a compromise on one system could lead to widespread exposure of data across an organization's entire physical security network. This scenario aligns with MITRE ATT&CK technique T1538, which involves gathering information about cloud infrastructure or software configurations, and specifically relates to the exploitation of weak cryptographic implementations as described in various advisory frameworks regarding insecure cryptography storage.
Mitigation strategies must prioritize immediate remediation through vendor-provided updates. Organizations running Kantech Entrapass versions earlier than 9.20 should apply the latest available patch which addresses this flaw by replacing hard-coded keys with dynamically generated, unique session-specific or device-specific cryptographic material. Until patches are applied, network segmentation is recommended to restrict access to the vulnerable services from untrusted networks. Additionally, implementing strict monitoring for unusual decryption error rates can help detect ongoing padding oracle attacks in real-time. Long-term security posture improvements should include adopting a robust key management system that ensures keys are never hard-coded and are rotated regularly according to industry best practices such as NIST SP 800-57 guidelines on cryptographic key management.